Kelsay, who left practice Thursday with a neck injury, did not practice on Friday. He is listed as questionable for the game, but players that do not practice on Friday only rarely suit up on Sundays. If Kelsay cannot go, Kyle Moore will see increased playing time (and likely start), while Shawne Merriman - himself questionable with a chest injury - will likely get plenty of work, as well.
Two players have already been ruled out: defensive end Mark Anderson (knee) and cornerback Aaron Williams (knee), the aforementioned two starters. Anderson's absence, paired potentially with Kelsay's, could leave the Bills with just three active defensive ends. Leodis McKelvin - listed as probable with a groin injury - will replace Williams in the starting lineup opposite Stephon Gilmore (also probable with a shoulder problem).
Aside from Kelsay, four more players are questionable: Stevie Johnson, Kraig Urbik, Kyle Williams and Spencer Johnson. All four players are expected to suit up on Sunday, as are the other eight players not previously mentioned that are listed as probable: C.J. Spiller, Brad Smith, Chris Hairston, Andy Levitre, Eric Wood, Mario Williams, Marcell Dareus and Justin Rogers.